1999 Mitsubishi Montero 6 cyl Four Wheel Drive Automatic
I have a '99 montero sport 4wd xls, I keep having the check engine light coming on. I had the exhaust system replaced(aftermarket) and the catalyst(aftermarket) and even more recently the 02 sensors(dealer parts). Now the check engine light came on again code read po420-which is catalyst effeciency. Any idea what it could be?
Friday, October 15th, 2010 AT 6:03 PM